Each year in North America, many thousands of motorcyclists die in collisions with automobiles and trucks. In many of these accidents, the driver of the automobile or truck claims not to have seen the motorcycle. Because motorcycles subtend a much smaller angle of the visual field than do cars (particularly in front view), a motorcycle whose image falls on the peripheral retina of an automobile or truck driver may not generate sufficient motion induced activity in retinal neurons to render the motorcycle salient to the car or truck driver.
A number of prior art devices are known for heightening the awareness of automobile and truck drivers to the presence of motorcycles. For example, U.S. Pat. No. 4,241,328 (Lobe et al) teaches a circuit arrangement for the turn indicator blinker lights of motorcycles. When the motorcycle is moving (i.e. not in neutral and with the clutch engaged) and one of the turn indicators is activated, a buzzer is activated to provide a combined audible and visible signal. When the clutch is disengaged or the transmission is in neutral, then the buzzer or horn is left inactivated when the turn signal is activated.
U.S. Pat. No. 4,812,808 (Ulrich) discloses a lighting system for motorcycles with minimal wiring cables and harnesses.
U.S. Pat. Nos. 3,916,377 (Demeter) and 4,051,361 (Lichon et al) disclose prior art signal devices for use with motorcycles to identify the presence of a motorcycle. Each of these patents discloses a flasher mounted to the top of a mast at the rear-of the motorcycle. The '361 Patent specifies that left and right turn indication is possible.
U.S. Pat. No. 4,127,844 (Purdy) discloses a high intensity electronic flasher warning system which operates in the range of 60 to 100 flashes per minute (i.e. 1 to 1 2/3 Hz). The flasher is activated by either the brake, turn or emergency flash circuits of the motorcycle.
U.S. Pat. No. 4,550,305 (Bookbinder) also discloses a pulsating lighting system for motorcycles in which a first strobe is associated with the headlamp and a second strobe is associated with operation of the tail light. The strobes are indicated as operating in the range of 1 to 2 Hz.
Another prior art visual warning system is available for bicycles and is manufactured under the trade name "Vistalite" by Vistalite Inc. of Lancaster, Pa., U.S.A. The "Vistalite" system generates a flicker frequency between 4 Hz and 6 Hz.
Although the above discussed prior art warning systems are known to improve driver awareness to the presence of motorcycles and bicycles, none of the prior art systems maximize the visual salience of images falling on the retinal periphery (i.e. so as to call the driver's attention to objects and hazards that are not being directly looked at).